1. Field of the Invention
This invention relates to general purpose dollies and, more specifically, to a dolly suitable for stacking a plurality of like dollies to minimize space requirements when the dollies are not in use.
2. Description of the Prior Art
Many dolly designs have been proposed for use in moving generally heavy objects. Many of the known dollies can be stacked. However, because they are not generally designed to optimize stacking, when many such dollies are stacked they do not generally stay aligned along a vertical direction but the column of dollies tends to incline or lean from the vertical and become unstable, possibly creating a dangerous condition since the stack may topple and cause injury. Examples of some prior art dollies are disclosed in the following patents:    U.K. Patent No. GB2229151;    U.K. Patent No. GB727568; and    U.S. Pat. No. 5,445,396.
In U.S. Pat. No. 5,823,549 a stacking dolly is disclosed that is specifically designed to render the dolly stackable while rendering a stack of such dollies stable even when a relatively large number of dollies stacked one on top of the other. However, the design disclosed in this patent relies on the use of depressions or apertures in the upper surfaces of the dollies and projections or protuberances projecting downwardly from the dollies intended to be received within the recesses or depressions of adjoining dollies on which they are supported. The problem with this design is that the projections or protuberances need to be precisely aligned with the recesses in a next lower dolly and proper stacking cannot take place unless the projections are received within the cooperating recesses or apertures. However, this may be somewhat inconvenient and time consuming and professionals, such as movers, may not have or wish to take the time out to carefully stack the dollies to make sure that they are properly aligned to optimize the design feature of the dolly.